The present invention relates to an underwater pin and socket type connector for making connections of electrical or fiber-optic circuits in harsh environments, such as great ocean depths.
There are many types of connectors for making electrical and fiber-optic cable connections in hostile environments. One type includes connectors for undersea mating and demating. Such underwater connectors typically comprise a plug unit containing one or more contact probes and a receptacle unit containing an equivalent number of receptacle contacts or junctions for engagement with the contact probes, which extend into the receptacle unit when the units are connected together. Typically, the contacts or junctions are contained in a sealed chamber containing dielectric fluid, and the probes enter the chamber via one or more normally sealed openings. One major problem in designing such units is the provision of seals which will adequately exclude seawater from the contact chamber even after repeated mating and demating, and also prevent dielectric fluid from leaking out of the chamber.
A number of different sealing mechanisms have been proposed in the past for achieving this objective. One such sealing mechanism has an opening into the contact chamber which comprises an elastomeric tubular entrance surrounded by an elastomeric sphincter which pinches the entrance closed upon itself when the plug and receptacle units are in an unmated condition. In the mated condition, the sphincter pinches against the entering probe to form a seal. Although this type of seal is successful in some cases, it does have disadvantages. One disadvantage is that this seal does not work well under all hostile conditions. Another disadvantage is that such seals tend to lose their "memory" after repeated mating and demating, so that they may fail to close completely, or may not close quickly enough to isolate the chamber from the surrounding environment when the units are demated. Another type of known seal mechanism comprises a piston which moves axially into the seal opening as the units are demated.
In some known underwater electrical connectors, such as that described in my U.S. Pat. Nos. 4,795,359 and 5,194,012, tubular socket contacts are provided in the receptacle unit, and spring-biased pistons are urged into sealing engagement with the open ends of the socket assemblies. As the plug and receptacle units are mated, pins on the plug portion urge the pistons back past the contact bands in the sockets, so that electrical contact is made. However, this type of arrangement cannot be used in an optical connector since the optical contacts must be able to engage axially for practical purposes.
Underwater electro-optical connectors are described in U.S. Pat. Nos. 4,616,900 and 4,666,242 of Cairns. In U.S. Pat. No. 4,666,242 , the male and female connector units are both oil filled and pressure balanced. This device utilizes a penetrable seal element having an opening which pinches closed when the units are separated. Other known fiber-optic connectors have similar seals which are not suitable for use under some conditions and may tend to lose effectiveness after repeated mating and demating.
Known seal mechanisms are not completely effective in providing repeatable, reliable optical and electrical connections in adverse environments while maintaining electrical or optical contacts or terminals in isolated chambers at all times. Optical connectors which are currently available are extremely expensive and generally require complicated means for terminating the connector elements or junctions to the cables they are intended to connect. Up to now, none of the known connectors have been ideal for making repeated and reliable optical and electrical connections in hostile environments such as the greatest ocean depths.